Article Early earth was not hellish + Fossil tracks show fish adapting to movement on land

[C C]

Fish tracks show earliest adaptations for moving on land
https://phys.org/news/2025-08-fish-tracks-earliest.html

INTRO: The Polish Geological Institute-National Research Institute reports a Lower Devonian (419 to 393 million years ago) fossilized trackway in the Holy Cross Mountains, Poland, attributed to dipnoan fish. Their analysis finds what appears to be the earliest record of fish testing the land mobility skills of vertebrates, predating by about 10 million years the first evidence of fully terrestrial tetrapod locomotion.

Preadaptation to the invasion on land is a requirement for later, more permanent stays, likely motivated by gaining access to new feeding areas during low tide. Few sites have recorded locomotion traces from the first vertebrates to colonize land, mainly from Europe and one from Australia, with the previous oldest to date coming from the lower Middle Devonian of the Holy Cross Mountains, Poland.

Numerous terrestrial locomotory traces of a similar age occur on Valentia Island, Ireland. Evidence indicates tetrapods were already capable of efficient locomotion on land at the beginning of the Middle Devonian, suggesting that the origins of quadrupedalism should be sought in even older formations.

In the study, "Traces of dipnoan fish document the earliest adaptations of vertebrates to move on land," published in Scientific Reports, researchers analyzed newly excavated trace fossils and 3D scans to interpret the locomotion and snout anchoring attributed to dipnoan fishes... (MORE - details)

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Life on Earth emerged far quicker than we thought: Early Earth was not hellish
https://aeon.co/essays/life-on-earth-eme...we-thought

INTRO: Here’s a story you might have read before in a popular science book or seen in a documentary. It’s the one about early Earth as a lifeless, volcanic hellscape.

When our planet was newly formed, the story goes, the surface was a barren wasteland of sharp rocks, strewn with lava flows from erupting volcanoes. The air was an unbreathable fume of gases. There was little or no liquid water. Just as things were starting to settle down, a barrage of meteorites tens of kilometres across came pummelling down from space, obliterating entire landscapes and sending vast plumes of debris high into the sky. This barren world persisted for hundreds of millions of years. Finally, the environment settled down enough that oceans could form, and the conditions were finally right for microscopic life to emerge.

That’s the story palaeontologists and geologists told for many decades. But a raft of evidence suggests it is completely wrong.

The young Earth was not hellish, or at least not for long (in geological terms). And, crucially, life formed quickly after the planet solidified – perhaps astonishingly quickly. It may be that the first life emerged within just millions of years of the planet’s origin.

With hindsight, it is strange that the idea of hellscape Earth ever became as established as it did. There was never any direct evidence of such lethal conditions. However, that lack of evidence may be the explanation. Humans are very prone to theorise wildly when there’s no evidence, and then to become extremely attached to their speculations. That same tendency – becoming over-attached to ideas that have only tenuous support – has also bedevilled research into the origins of life. Every journalist who has written about the origins of life has a few horror stories about bad-tempered researchers unwilling to tolerate dissent from their treasured ideas.

Now that the idea of hellscape Earth has so comprehensively collapsed, we need to discard some lingering preconceptions about how life began, and embrace a more open-minded approach to this most challenging of problems. Whereas many researchers once assumed it took a chance event within a very long timescale for Earth’s biosphere to emerge, that increasingly looks untenable. Life happened fast – and any theory that seeks to explain its origins now needs to explain why... (MORE - details)

[Yazata]

https://aeon.co/essays/life-on-earth-eme...we-thought

INTRO: Here’s a story you might have read before in a popular science book or seen in a documentary. It’s the one about early Earth as a lifeless, volcanic hellscape.

When our planet was newly formed, the story goes, the surface was a barren wasteland of sharp rocks, strewn with lava flows from erupting volcanoes. The air was an unbreathable fume of gases. There was little or no liquid water. Just as things were starting to settle down, a barrage of meteorites tens of kilometres across came pummelling down from space, obliterating entire landscapes and sending vast plumes of debris high into the sky. This barren world persisted for hundreds of millions of years. Finally, the environment settled down enough that oceans could form, and the conditions were finally right for microscopic life to emerge.

That’s the story palaeontologists and geologists told for many decades. But a raft of evidence suggests it is completely wrong.

That sounds like another example of what I call The Professor's Conceit, the claim that 'Everthing you think you know is wrong. Let ME reveal the truth.' Sorry, but I just don't accept that hubris any more.

It's easy to explain: Scholars don't make names for themselves by agreeing. They become known for advancing ideas that get their peers talking and get their papers heavily cited.

It just stands to reason, by me anyway, that if the Earth formed from the accretion of planetesimals in the Sun's early accretion disk, then that accretion process must have taken a considerable amount of time. And the proto-Earth would most emphatically have been uninhabitable while it was happening. In other words, the Earth didn't just pop into existence fully formed 4.5 billion years ago, with conditions similar to present day immediately after, and no Earth at all prior.

The young Earth was not hellish, or at least not for long (in geological terms).

Perhaps they are underestimating the age of the Earth. Extend it from 4.5 billion years old to perhap 5 billion years old. With most of the "hellish" accretion and post-accretion processes prior to 4.5 billion years ago. That way, the accumulating evidence of liquid water on the Earth increasingly close to the hypothesized (but perhaps not really) 4.5 billion year old origin becomes more likely.

And, crucially, life formed quickly after the planet solidified – perhaps astonishingly quickly. It may be that the first life emerged within just millions of years of the planet’s origin.

Which would be an excellent argument for panspermia in my opinion.

With hindsight, it is strange that the idea of hellscape Earth ever became as established as it did.

1. The accretion process itself. 2. The formation of the Moon, if as hypothesized it is the result of an early collision between the proto-Earth and a Mars sized body. If that collision really happened, it would have left what remained of the Earth a spheroid of molten rock. 3. The evidence on the cratered face of the Moon of the Late Heavy Bombardment by countless smaller bodies.

Now that the idea of hellscape Earth has so comprehensively collapsed, we need to discard some lingering preconceptions about how life began, and embrace a more open-minded approach to this most challenging of problems. Whereas many researchers once assumed it took a chance event within a very long timescale for Earth’s biosphere to emerge, that increasingly looks untenable. Life happened fast – and any theory that seeks to explain its origins now needs to explain why...

Yes, I agree that what appears to be the early appearance of life on Earth does cry out for explanation and creates challenges for theories of life's origins. It's why I'm increasingly attracted to panspermia.

Even the simplest prokaryotic cells are so incredibly complex (wonders of nanomachinery at the atomic level) that their initial appearance must have been the result of elaborate pre-biotic chemical processes. Processes that humanity will probably never fully understand, if only because we can't go back in time to observe what actually happened. Given the complexity of the processes that would give rise to even the simplest cells, it's reasonable to hypothesize that it must have taken an extended period of time. And if, as the author argues, life appeared on Earth so early that the time available had to have been extremely short, then it becomes reasonable to hypothesize that maybe the origin of life occurred elsewhere.

And in all fairness, the article that CC links to is a lot better than its opening paragraphs. The author discusses much of this stuff. It's well worth reading.